Who is Marie-Jean de Villiers, Marquis de Tilbot from Parrot and Olivier in America and what is their importance?

Marie-Jean de Villies, the Marquis de Tilbot, is known as the Hero of the Vendee. He is a one-armed spy during the French Revolution, after which, he ends up in England, where he rescues Parrot from the fire at the Piggotts' printery. Tilbot abandons Parrot on a boat to Australia but returns for him when he becomes an adult. Tilbot successfully convinces Parrot to leave his home and family to become an artist in Paris. He employes Parrot for many years, and he even talks him into accompanying Olivier to America.